He later became the unofficial editor-in-chief for Monthly Shonen Sunday after its creation in 2009. Ichihara then was promoted to editor-in-chief of Weekly Shonen Sunday in 2015, where he started his position by putting a page-wide declaration in Sunday stating that the magazine would make nurturing new mangaka their first priority. This "Sunday Reform" would ultimately save Weekly Sunday at a time where editors were afraid the magazine would go out of business, as the influx of new mangaka allowed Sunday to provide hit after hit.
Ichihara retired from his position in 2021 to change gears and work as a mangaka himself.